PURPOSE: To improve the fuel consumption rate while assuring the traveling performance by generating a shift indication during the warm-up on the higher rotation side by a predetermined value compared with that after the warm-up.

CONSTITUTION: This device has a clutch switch 54 for detecting the existence of a clutch operation based on the depressed condition of a clutch pedal 52, a shift direction indicator lamp 56 for displaying the shift direction at an optimum shift timing, and a speaker 58 for generating its acknowledge sound. The ECU42 is provided with a calculating function determining an apparent engine rotation speed by subtracting a predetermined value X from the engine rotation speed during the engine warm-up, a memory function with a shift-up area and a shift- down area set corresponding to the rotation speed and load, and a data processing function outputting indication signals to the shift direction indicator lamp 56 in response to the apparent rotation speed and load during the warm-up, and on the other hand, in response to the actual rotation speed and load after the warm-up respectively.